


Simple Romance

by todxrxki



Series: Kuroken Week 2020 [5]
Category: Haikyuu!!
Genre: Alternate Universe - Siblings, Didn't Know They Were Dating, Gen, M/M, featuring oblivious kenma and kuroo, i just wanted to explore the dynamic of kenma with a sister, in which kenma has an older sister
Language: English
Status: Completed
Published: 2020-04-17
Updated: 2020-04-17
Packaged: 2021-03-01 19:35:17
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,715
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23702425
Author URL: https://archiveofourown.org/users/todxrxki/pseuds/todxrxki
Summary: There’s only ever been one thing Kana has wanted for her brother, Kenma, and that’s for him to be happy. And in that moment, she’d been suddenly sure that having someone who loves him as completely as Kuroo loves him would be a great contributor to his happiness. / In which Kozume Kenma's older sister speculates on the nature of her brother's relationship with Kuroo Tetsurou - and can't help but intervene.
Relationships: Kozume Kenma/Kuroo Tetsurou
Series: Kuroken Week 2020 [5]
Series URL: https://archiveofourown.org/series/1701457
Comments: 26
Kudos: 298
Collections: Kuroken Week 2020, My favorite haikyuu fics





	Simple Romance

Kozume Kana has spent a lifetime worrying after her little brother.

It’s not that he can’t take care of himself. He can, when he wants to. He shows remarkable survival and critical thinking skills when it comes to his games, after all. But sometimes he forgets to do basic things like  _ eat _ , and sometimes Kana thinks that he might even forget to breathe. And beyond that, she just wants her brother to be happy. Watching him in his first couple years of school had been… heart-wrenching, to say the least.

“Kenma!” she’d yell, meeting him at the front door. “Hey, Kenma! How was your day at school?”

“...fine,” Kenma would mumble in response, his big golden eyes trained on the ground.

“You meet anyone cool?”

“Uh, no,” Kenma’d said back then, crossing his arms across his chest. “Not really.” 

She had sighed, putting down her bag. “Just keep tryin’! Be yourself! And like, talk to people! You’ll meet friends in no time!” 

But he hadn’t. Day after the day, it’d been the same conversation, and Kana had contemplated marching into the kid’s classroom herself to make friends  _ for  _ Kenma. 

But then Kuroo Tetsurou showed up.

Her mother had ushered both children to the door, greeting the man and child that had walked in with a smile on her face. “I’m Kozume Kimiyo, and these are my children, Kana and Kenma.”

“Ah, Kenma-kun seems like he’s about Tetsu-kun’s age,” the man had said fondly. “I’m Kuroo Hachiro. This is my son, Kuroo Tetsurou. Thank you for inviting us.”

“Kenma, honey, why don’t you go take Tetsu-chan up to your room?” her mother said. “You two can play together.”

Kenma had wrinkled up his nose, the way he always did when he didn’t want to do something, but motioned the other boy to follow him. The boy finally came out from behind his father’s leg - showing a full head of messy hair and a slight frown. Admittedly, Kana’s first thought was that she wasn’t sure if the two would get along. So she’d followed them up the stairs like the nosy girl she’d always been and pressed her ear to the door.

“We can play this game, if you want.” The quiet voice was definitely that of her brother. He was talking to someone his own age, she thought with a thrill of joy. Finally! 

“Okay,” came the other boy’s quiet voice. Then there was silence - just the clicking noise of controllers. Well, it wasn’t much, Kana had thought despairingly. Still, it was better than nothing. It was better than Kenma’s despairing face, coming home from school each day to report he’d talked to absolutely no one. So Kana counted it as a victory.

She had simply hoped that it wouldn’t be the last she saw of Kuroo Tetsurou. And, shockingly enough, it wasn’t.

At first it was only one day a week that she’d come in from her after-school clubs to see Kuroo seated at their kitchen table, eating a snack with Kenma. But then it became two days a week, then three. And pretty soon it had become basically every day.

“Hey,” she’d said to Kuroo one day when he was walking down the stairs, a ball in his hands - a volleyball, she’d thought. “Where are you headed to?”

At that point, she’d rarely spoken to Kuroo, and he was still in his shy stage, so he’d turned away, his cheeks red. “Um,” he’d said. “Kenma and I are gonna go play volleyball.”

Kana remembers that her eyes had practically popped out of her skull. “ _ Kenma’s  _ gonna play volleyball?”

“Yeah,” Kuroo’d said, sounding a tiny bit more enthusiastic all of a sudden. “He hasn’t played before or anything, but I think he could be really good. He has a really… like, he comes up with good strategies!”

“This I’d love to see,” Kana’d replied with a laugh. “I wish you the best of luck.”

Kuroo had brushed past her then, running down the stairs and calling for Kenma. So later that night, Kana had slipped into Kenma’s room, crossing her arms. “You play volleyball now?”

“Just with Kuro,” Kenma’d said.  _ Kuro,  _ she noted - not  _ Kuroo.  _ At some point over the last few weeks Kuroo had become  _ Kuro  _ to Kenma. That was something new, certainly. Her brother had never become close enough to anyone to give them a nickname before. 

She’d blinked at him. “The two of you seem pretty close these days.”

“I guess,” Kenma’d said with a shrug, in typical Kenma fashion. Everything was an “I guess” with him, never any certainty in his answers. “He’s usually not annoying, and he’s not bad at games.”

The two criteria it took to be her brother’s friend, Kana had thought, shaking her head. “Well, that’s good, then. I’m glad you finally found someone you actually like.”

And so he did. Somehow, through Kenma’s influence also, Kuroo became more outgoing as well. It started off with just simple greetings or nods when she entered the room, then short conversations, and eventually she’d walk in the door and he’d grin and wave at her. “Good afternoon, Kana-san! How was your day today?”

After the tenth time or so, Kana shook her head. “Just call me nee-san.” Kuroo’s constant presence in the family meant that he’d become something like a younger brother to her, so she figured it was only right.

“Nee-san,” Kuroo had repeated with a grin. Then, turning to Kenma and grabbing his hand, he’d said, “C’mon, Kenma, let’s go do some special attacks!”

“Kuro, you really need to stop watching so much TV,” Kenma’d grumbled in response. “They can do it because they’re taller and older than you, but you can’t jump that high.”

“I’ll be able to one day! Which is why we need to keep practicin’, see.”

“I guess,” Kenma had relented, letting Kuroo pull him out the door.

They’re good for each other, Kana remembers thinking. Kenma makes Kuroo more outgoing and confident; Kuroo makes Kenma more sociable and active - they counterbalance each other. It’s something that’s still true to this day, something that may always remain true, she’s pretty sure.

By the time Kenma had gotten to middle school, though, his friendship with Kuroo took yet another surprising turn. Kana herself had dabbled in a few sports in middle school: volleyball for a short period of time, softball temporarily, but then she’d decided that music and art were more her thing than getting all sweaty and gross for no good reason. She’d never thought in a million years that Kenma would join any kind of sport, pretty much ever.

But he sat down at their dinner table and quietly said, “I’m joining the volleyball team.”

Kana had sat in shock for a second, not expecting  _ those  _ words to come out of her brother’s mouth, while their mother had casually responded, “You’re joining the volleyball team? I didn’t know you were interested in volleyball.”

Kenma stared down at his plate. “Kuro asked me to.”

“Oh, Kuroo asked you to, huh? That explains it  _ allll _ ,” Kana had replied teasingly, kicking her brother’s foot under the table. 

Kenma scowled at her in response, his trademark scowl that he got whenever Kana teased him about anything - which was fairly often, to be honest. “Shut up.”

“Be nice, both of you,” his mother scolded them. “Kenma, we’ll have to come see the two of you play some time! Actually, I’m surprised that he’s not here for dinner tonight.”

“He’s playing soccer with some guys down the street,” Kenma had replied. “But he said he’d come by afterwards to come see my new game… if that’s okay.”

“Of course, you know Tetsu is always welcome here,” their father had replied fondly, and Kana just smiled too, shaking her head. Of course it would be Kuroo that could get her brother onto a sports team. Well, if it was improving his health, who was she to complain?   
  


After that, she’d catch them walking home from the middle school while she was on the way home from play rehearsals. They’d be walking closely, Kuroo’s hands moving like he was explaining something animatedly to Kenma while Kenma watched him with wide eyes. 

Back then, Kana hadn’t known exactly what to think: merely that they were  _ very  _ close, in a way that most friends weren’t. She’d shrugged it off for a while. 

But then at play practice, one of the lead actresses had asked her to stay after rehearsal for a chat. This lead actress in particular was gorgeous, her long, black wavy hair framing her heart-shaped face and dark eyes perfectly. And she was incredibly talented: only a year older than Kana, if that, and yet had been the lead actress for most of the plays their club had put on. “Hey, Kana,” she’d said, leaning in close, and Kana’s heart had leapt in her chest, the steady drumming that usually resided there suddenly picking up speed. Then she’d pulled back. “Sorry, I just wanted to get a better look at your makeup. You’ve always been really good at doing makeup. Do you think you’d be possibly interested in picking up some makeup duties in Drama Club?” 

Kana coughed, the only way she could think of to explain her sudden lack of ability to speak. “Oh, uh, yeah. I could definitely do that.”

But on the way home that night, she had started to contemplate. She’d been aware of other sexualities before, though she’d never really been exposed to them all that much. Could she possibly be attracted to women? The lead actress had been  _ gorgeous,  _ that much she was certain of. Was that all it took? Could she see herself dating a woman? 

If she was being honest, she could. She could see her own hand trailing down a woman’s cheek, pressing her lips against a girl’s soft lips, a girl’s hand resting on her hip. And then she’d thought, wow, she could possibly be… into women. Gay in some way, she’d supposed. It was a weird realization, one she’d keep internalized for a while. However, it was this realization that also made her start speculating about the nature of her own brother’s relationship with his best friend. 

She graduated high school, and even as Kuroo and Kenma moved into high school, nothing about their relationship really shifted. In fact, it seemed to her as though they’d just gotten closer. She came home one weekend from college to find Kuroo and Kenma on the couch together, Kuroo’s arm draped around Kenma’s shoulders, Kenma’s head resting on Kuroo’s shoulder. She’d raised an eyebrow, but decided not to press the issue. “Hey.”

Kuroo had been the first to get up to hug her, and then Kenma, as affection-avoidant as ever, had come after, giving her barely a squeeze before he let go. “Welcome home,” Kenma had mumbled. 

“Thanks,” Kana had replied. “What are you guys watching?” 

“Some stupid drama series,” Kenma’d replied. “It was Kuro’s idea.”

“Not sure if Kenma’s been so much watching as taking a nap on my shoulder,” Kuroo had drawled. 

“Wouldn’t put it past him,” Kana had said, shaking her head fondly. “He’d fall asleep during every good movie when we were kids, remember? Always during the best fuckin’ parts, too.”

“I did not,” Kenma had replied, crossing his arms.

“You did,” Kuroo sing-songed. “Hey, I’m gonna get a drink. You want anything, Kenma?”

“Coke.”

“No way. You need to cut down on your soda intake,” Kuroo had responded with a frown. “I’ll get you a water.”

“Good idea,” Kana had said, grinning. “Someone’s gotta look out for Kenma’s health, and that person is not gonna be Kenma.” 

“Ugh,” Kenma had groaned. “You two are always ganging up on me. Why ask me what I want to drink if you’re not even going to get it?”

“Because I care about you and your health. Sue me,” Kuroo had said, setting down a cup of water beside Kenma. Kana had glanced at him to see there was a hint of a smile on his face, the smile too loving to be purely friendly, and the gears in her head had started turning even faster. 

There’s only ever been one thing Kana has wanted for her brother, and that’s for him to be happy. And, therefore, in that moment, she’d been suddenly sure that having someone who loves him as completely as Kuroo loves him would be a great contributor to his happiness. She’d put a hand on her chin in contemplation. 

And then Kuroo and Kenma had started to get even  _ closer.  _ She’d come home from school for breaks or weekends to find them cuddling, whether in Kenma’s bed or on the couch. They’d invite her out and go off on their own, holding hands, Kuroo looking at her brother like he was the most precious thing on the entire planet. And they hung out basically all the time. But they had never actually  _ confirmed  _ that they were dating or anything. 

Kana likes to think of herself as a patient person. (It’s probably not the truth, if she’s being honest, but she likes to to pretend.) However, her patience has its limits. And not being told something this important by her younger brother, something that she can clearly witness herself, is starting to grind on her nerves.

Which brings her to the current moment. She’s just come home to find Kenma, who, for once, is alone on the couch. Wrinkling up her nose, she plops down beside him and ruffles his hair. Kenma winces away from her touch, giving her an elbow that she expertly dodges. “Hey, where’s the boyfriend?”

Kana had expected some sort of recognition from her younger brother, shock that she’d figured it out or a smile that she’d finally caught on or  _ something.  _ Instead, all that showed up on Kenma’s face was confusion. “The what?”

“Boyfriend…” she repeated, but there was still no sign of any sort of recognition on Kenma’s face. She sighed. “Kuroo.”

Kenma’s face twisted. “Kuro’s not my boyfriend.”

Kana narrows her eyes, but then says, “Kenma, you know you can tell me anything, right? You being into guys won’t change my opinion of you. At all. Especially if it’s Kuroo. I’ve been budgeting him into the family for years now.”

Kenma folds his arms across his chest. “I’m being serious right now,” he says flatly, in a tone that leaves no room for Kana to believe he’s lying any longer. “Kuro and I are just friends.”   
  


Now it’s time for Kana to be confused. Her confusion displays itself through incredulous laughter, though - loud and piercing through the air between them, until finally she shakes her head to calm herself down. Kenma gives her a slight glare, a glare that she’s come to understand as him conveying that he’s serious. She shakes her head. “I know, I know. I just… you know you guys are basically dating, right?”

“I have no idea what you’re talking about.”

“Come on. I know you’re not the most experienced in this department, but you guys are always touching - “

“Kuro’s just affectionate.”

“And you go out alone together every weekend -”

“We hang out together. That’s normal best friend stuff.”

“You hold hands -”

“It’s comforting."

"Kenma,” Kana says, shaking her head. “Say the two of you were dating. What exactly would you be doing differently?”

Kenma’s cheeks turn a little bit red. “I’m not talking about that with you,” he says.

“Beyond kissing and sex and all that shit,” Kana replies, rolling her eyes. “Anything else you’d do differently?”

Kenma glances away stubbornly. He’s silent for a few seconds, probably in realization, and then his lips tilt even further down. “...I guess not.”

“Fine. Then just answer me this,” Kana says. “Do you love him? And don’t say as a friend or whatever to get out of answering the question.” 

“I…” Kenma says, biting down on his lip. He turns around. “I… yeah. I think I do.”

“Okay,” Kana replies. She’s not surprised in the least, of course; she would’ve been much more surprised had Kenma said that he didn’t love Kuroo. “In that case, why not give it a shot?”

“Who says Kuro feels the same way?”

Kana shoots him a look - an ‘are-you-kidding-me’ look - but Kenma doesn’t back down from his stubborn glare in return. Finally, refusing to back down but still wanting the best for Kenma, she groans. She knows that Kenma won’t say anything of his own volition out of fear that Kuroo will reject him - a ridiculous fear, of course, but there’s nothing Kana can say to change his mind. So she says, “I’ll talk to him, then.”

“Don’t.”

“I’m going to,” Kana says stubbornly. “But I won’t say anything about what you told me.”   
  


Kenma gives the world’s most dramatic, long-suffering sigh, and sinks back into the couch, giving her a dark glare. “Whatever,” he says in assent, and it’s the best confirmation Kana’s going to get that she’s doing the right thing.

So a couple of days later, Kenma goes out to meet someone: not Kuroo for once, someone else from his team, he says. But Kuroo shows up nonetheless. Kana figures Kenma hadn’t told him not to come so that Kana can talk to him, and she chuckles to herself. Her younger brother is kind of adorable sometimes in his methods. “Hey. Kenma’s not here.”

“Eh?” Kuroo says, raising an eyebrow. “Where is he?”

“Meeting some other guy on your team for something? Dunno,” Kana says. 

“He’s so social these days,” Kuroo replies in a tone that’s somewhat bittersweet. “Going out and making friends of his own volition.”

“Hm? Like who?” Kana asks. 

“This shorty from Karasuno,” Kuroo gripes. “He’s all bright and talkative and he can jump like nobody’s business, and now that we’re playing against Karasuno Kenma’s suddenly all interested in volleyball.”

Kana raises an eyebrow at him. “You don’t sound happy about it.” 

Kuroo breathes in deeply, then says quickly, “I am. Don’t get me wrong, of course I am. There’s nothing I want more in the world than for him to be happy.”

The two of them couldn’t be less subtle if they tried. Everything about Kuroo’s words screams that he’s in love with Kenma. So Kana just says, “Then our goals are the same. Just save us some time and tell him you love him already, would you?”

Kuroo gives her the reaction she was hunting for. His eyes widen; his head whips around to look at her, eyes as big as saucers. “H-how…” he stutters out.

“You’re not subtle,” she says. “You’re upset that he’s hanging out with other people, even though you don’t wanna be. You look at him like he’s, like, the most fuckin’ beautiful person to exist ever in the universe.”

“He is,” Kuroo says, and then groans. “Okay, yeah, I’m not subtle. But what the hell can I even do about it?”

“Tell him.”

“What, you seriously think he’d want to be told?! You know Kenma. He’s not… into stuff like that.”

Kana sighs deeply. “Wanna know something, Tetsu-kun?” Kuroo nods, and after a pause (for dramatic effect, of course), Kana continues. “When Kenma was a kid, before you met him, he’d come home every day with this sad expression on his face. He didn’t have friends. He didn’t talk to anyone, really. I didn’t want to give up hope, but it started to seem impossible that he’d find someone that he genuinely liked, and that accepted him in return. And then, just when he really needed someone, you showed up. Therefore, I guess what I’m trying to say is that for Kenma, you’ve always been an exception. You’re the first person to really accept him. You’re special to him.”

Kuroo looks absurdly pleased at this bit of information, his cheeks pink and eyes big, but then he quickly says, “That doesn’t mean I’m an exception romantically.”

Kana is becoming tired of this conversation very quickly. “Tell. Him.”

“Fineeee,” Kuroo bemoans. “But only because it sounds like you know something you’re not saying, nee-san.”

“My lips are sealed,” Kana says, but she’s pretty sure there’s a twinkle in her eyes that she can’t quite cover up. She’s never been great at bullshitting, after all. And that’s probably why Kuroo looks somewhat excited as well. 

Surprisingly, it doesn’t take very long after that. Two days later, she walks by Kenma’s room to see Kuroo pressing Kenma into the wall, his hand cupping Kenma’s cheek and the other entwined in Kenma’s hair as he kisses him. Standing in the doorway, she clears her throat, and the two spring apart immediately.

“When was I going to be informed about this?” she asks, leaning against the doorframe.

“To be fair,” Kuroo says sheepishly, rubbing at the back of his neck, his cheeks completely red, “it kind of just happened. So you’re still the first to know.”

She laughs. “Well, congrats. Even though I gotta say I saw it coming from a mile away.”

“You’re… really okay with this,” Kenma says, his voice too small: as though he’s worried she would say no. As if she could ever say no.

She laughs. “Not like I of all people could judge. Y’know, I’m pretty open when it comes to who I could date, to put it lightly.”

“You… oh,” Kenma says, while Kuroo just grins, draping an arm around Kenma’s shoulder. “Runs in the family,” Kuroo says, to which Kenma rolls his eyes and nudges Kuroo away.

“I have two conditions, though,” Kana says. 

“Go for it,” Kuroo replies.

“First, I get to be the maid of honor at your wedding. And second, Kuroo, if you have any cousins that are hot… let me know. I'm open to anyone at this point.”

“Deal,” Kuroo says, going in to hug her, and Kenma doesn’t hesitate a second - for one - before he joins the hug. 

“Also,” she mumbles into Kuroo’s shoulder, “close the door next time, would ya?” Both of them look at her with guilty eyes before they nod in unison.

All Kana’s ever wanted is for her little brother to be happy, she thinks. And, she sees in both of their eyes: there’s no one in the world that can make him happier than Kuroo Tetsurou.

**Author's Note:**

> Here I am yet again with Kuroken Week: Day 4! I just had the idea of Kenma having an older sister and couldn't get it out of my head, and now I kind of love her and want to see her outside of a Kuroken fic. Anyways, I hope you all enjoy, and please leave a comment if you did!


End file.
